55SiCr弹簧钢连铸坯表面渣坑的研究与工艺控制  

Research and Process Control of Surface Slag Pits on 55SiCr Spring Steel Continuous Casting Billet

作　　者：孙俊喜 任刚 靳国兵 陈涛 李杰 Sun Junxi;Ren Gang;Jin Guobing;Chen Tao;Li Jie(Technical Center,HBIS Group Hansteel Company,Handan Hebei 056015,China)

机构地区：[1]河钢股份有限公司邯郸分公司技术中心,河北邯郸056015

出　　处：《山西冶金》2025年第1期123-125,共3页Shanxi Metallurgy

摘　　要：对修磨后的55SiCr弹簧钢连铸坯进行表面质量检查,发现第1炉第5流的1支铸坯角部存在渣坑缺陷,对缺陷位置取样,采用扫描电镜对渣坑内夹杂物质进行能谱分析,发现Na、F、K成分明显,为典型的结晶器保护渣成分,分析是结晶器保护渣卷入后形成。对生产过程控制情况进行检查,发现浇次第1炉浇注中后期,各流结晶器液面均存在异常波动的情况。通过对钢水化学成分进行研究,发现第1炉中间包钢水中Ca元素含量明显偏高。经调查,为保证浇次第1炉浇注过程稳定,避免因耐材、辅料等含Al增加钢水中Al含量,而在浇注过程中发生二次氧化生成Al_(2)O_(3)夹杂物,出现浸入式水口堵塞情况,在RH工序出站前向钢水中喂入钙线,使钢水中Ca含量偏高。但钢水中Ca含量的增加会加重对塞棒的侵蚀,导致塞棒表面出现掉块、结晶器钢液面出现异常波动,造成铸坯表面夹渣缺陷。在后续生产过程中严禁喂入钙线,避免中间包钢水中Ca含量异常增加,再未出现铸坯表面渣坑问题。Surface quality inspection was conducted on the 55SiCr spring steel continuous casting billet after grinding,and it was found that there was a slag pit defect at the corner of one casting billet in the first furnace and the fifth flow.Samples were taken from the defect location,and energy spectrum analysis was performed on the inclusions in the slag pit using scanning electron microscopy.It was found that Na,F,and K components were obvious,which were typical components of crystallizer protective slag formed after the crystallizer protective slag was rolled in.During the inspection of the production process control,it was found that there were abnormal fluctuations in the liquid level of each crystallizer in the middle and later stages of the first furnace pouring.Through the study of the chemical composition of molten steel,it was found that the Ca element content in the ladle steel water in the first furnace was significantly higher.After investigation,in order to ensure the stability of the first furnace pouring process and avoid the increase of Al content in the molten steel due to the presence of Al in refractory materials,auxiliary materials,etc.,Al_(2)O_(3) inclusions are generated during secondary oxidation during the pouring process,resulting in the blockage of the immersion water outlet.Calcium wire is fed into the molten steel before the RH process outlet,which increases the Ca content in the molten steel.However,the increase in Ca content in the steel water will exacerbate the erosion of the plug rod,leading to surface chipping and abnormal fluctuations in the crystallizer steel liquid level,resulting in slag inclusion defects on the surface of the casting billet.It is strictly prohibited to feed calcium wire during the subsequent production process to avoid abnormal increase of Ca in the water of the intermediate ladle,and to prevent the problem of slag pits on the surface of the casting billet from occurring again.

关 键 词：连铸坯 结晶器液面 保护渣 成分 钙线 

分 类 号：TG356.28[金属学及工艺—金属压力加工]